相量测量装置（PMU）基本功能应具有实时采集、监测、动态数据记录和实时通信功能。（）
参考答案：对
What __________ they putting on the Christmas tree?[ ]
A. was
B. is
C. are
计算3.6×0.25，最简便的算式是[ ]
A．3.6×0.2+3.6×0.05
B．3.6×0.5×0.5
C．0.25×4×0.9
